A system called a device server for connecting a device that only has a serial port to a computer network such as the Internet is known. For example, the vast majority of console ports that are provided on network appliances for making settings are serial ports. In Japanese Laid-Open Patent Publication No. 2002-328853, a serial port is connected via a device server to a network and a protocol is converted by the device server so that the console port of the network appliance can be accessed via the network and a parameter file can be set.
Although a device server has a function for converting a protocol and transferring data, the interface controller chip will differ depending on the protocol to be converted, and therefore it is necessary to use different device servers. For example, in Japanese Laid-Open Patent Publication No. 2002-328853, a mobile phone-compatible device server (DS) that is used to connect a mobile telephone and a serial port differs to a device server (DS) for connecting the Internet and a serial port.